低氧外泌体调控CSPCs归巢分化促进软骨原位再生的研究

软骨原位再生技术为软骨缺损修复提供了一种崭新的治疗方法，而软骨原位再生技术的核心—刺激干细胞迁移归巢至软骨缺损区依然是个难题。研究表明低氧环境可以促进干细胞归巢分化，而外泌体在传递细胞归巢分化信号过程中起着重要作用。因此，我们拟探索低氧预处理干细胞来源外泌体调控CSPCs归巢分化促进软骨原位再生的可行性及相关机制。首先，研究低氧对CSPCs体外迁移分化能力的影响；其次，研究低氧预处理的干细胞来源的外泌体对CSPCs体外迁移分化和体内归巢分化能力的作用。再次，过表达或干扰干细胞中HIF-1α后获取外泌体，评价外泌体介导HIF-1α对CSPCs迁移分化的影响；最后，将过表达HIF-1α的干细胞来源外泌体复合水凝胶移植到软骨缺损部位，探索低氧外泌体介导HIF-1α 调控CSPCs归巢分化促进软骨原位再生的相关机制。

Cartilage in situ regeneration provides a new option for cartilage defect repair, and the core of cartilage in situ regeneration--stimulating stem cells homing and differentiation in cartilage defect area， remains a difficult problem. Some studies indicated that hypoxia environment could promote the homing and differentiation of stem cells, and the exosomes plays a vital role in transmitting signal of cell homing and differentiation. Therefore, we try to explore the feasibility and mechanism of CSPCs homing and differentiation mediated by hypoxic exosomes in promoting cartilage in situ regeneration. First, we want to study the effect of hypoxia on migration and differentiation of CSPCs in vitro. Secondly, we would study the effect of exosomes derived from stem cells under hypoxia on the migration and differentiation of CSPCs, and the ability of homing and differentiation in vivo. Then, exosomes was harvested from stem cells treated with HIF-1 alpha over-expression or interfered with HIF-1 alpha shRNA, the impact of exosomes mediated HIF-1 alpha on CSPCs migration and differentiation was assessed; finally, exosomes from stem cell treated with over expression of HIF-1 alpha combined with hydrogel was transplanted into cartilage defects to explore the mechanism of HIF-1 alpha mediated hypoxia exosomes regulating CSPCs homing and differentiation in cartilage regeneration in situ.